The Fall of Shannara #1-2: Book Series by Terry Brooks
The 2-book set of mass market paperback novels includes the below titles:
The Black Elfstone (ISBN 9780553391503): Across the Four Lands, peace has reigned for generations. But now, in the far north, an unknown enemy is massing. More troubling than the carnage is the strange and wondrous power wielded by the attackers—a breed of magic unfamiliar even to the Druid order. Fearing the worst, the High Druid dispatches a diplomatic party under the protection of the order’s sworn guardian, Dar Leah, to confront the mysterious, encroaching force and discover its purpose.
But another crucial journey is being undertaken. Exiled onetime High Druid Drisker Arc has been living in quiet seclusion, far from the politics and power struggles of his former life, until two brutal attacks by would-be assassins force him to seek out an infamous murder-for-hire guild—and find the hidden enemy who has marked him for death. At his side is Tarsha Kaynin, a young woman gifted with the wishsong and eager to be schooled in its formidable power by a master. She, too, is pursuing a mission: to locate her wayward brother, whose own magic has driven him to deadly madness and kindled his rage for vengeance . . . against his sister.
In their darkest hours, facing dangerous adversaries, the lives and quests of Dar Leah, Drisker Arc, and Tarsha Kaynin will be inextricably drawn together. And the challenges each confronts will have resounding consequences for the future of the Four Lands.
The Skaar Invasion (ISBN 9780553391534): The Four Lands are under siege. Wielding a magical ability virtually impossible to combat, mysterious invaders defeat the most fearsome Troll armies, then focus their savagery on the Druid order—and all hope seems lost.
Eventually the invaders reveal a more human face, but understanding their motives in no way mitigates the brutality of their actions. Dar Leah, once the High Druid’s Blade, has crossed paths—and swords—with their ruthless leader before. So he knows that if any hope exists, it rests in the hands of the Druid Drisker Arc, now trapped inside vanished Paranor.
As Drisker races to find the ancient knowledge that could free him, Dar goes in search of Tarsha Kaynin, the young woman blessed with the powerful gift of the wishsong, whose magic could draw Drisker back into the world of the living. But little do they know that what appeared to be a formidable invading force may only be the forerunner of a much larger army—one intent on nothing less than total conquest.